Average Weather in Sisimiut Greenland
In Sisimiut, the summers are cold and mostly cloudy and the winters are frigid, snowy, windy, and overcast. Over the course of the year, the temperature typically varies from 2°F to 51°F and is rarely below -16°F or above 57°F.
Based on the tourism score, the best time of year to visit Sisimiut for warm-weather activities is from mid to late July.
The warm season lasts for 3.2 months, from June 6 to September 13, with an average daily high temperature above 43°F. The hottest day of the year is July 24, with an average high of 51°F and low of 41°F.
The cold season lasts for 3.3 months, from December 21 to March 31, with an average daily high temperature below 18°F. The coldest day of the year is February 24, with an average low of 2°F and high of 10°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
In Sisimiut, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Sisimiut begins around April 12 and lasts for 6.9 months, ending around November 8. On June 25, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 41% of the time, and overcast or mostly cloudy 59% of the time.
The cloudier part of the year begins around November 8 and lasts for 5.1 months, ending around April 12. On January 16, the cloudiest day of the year, the sky is overcast or mostly cloudy 85% of the time, and clear, mostly clear, or partly cloudy 15% of the time.
Cloud Cover Categories
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Sisimiut varies throughout the year.
The wetter season lasts 7.2 months, from April 28 to December 3, with a greater than 18% chance of a given day being a wet day. The chance of a wet day peaks at 28% on August 15.
The drier season lasts 4.8 months, from December 3 to April 28. The smallest chance of a wet day is 7% on February 16.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Sisimiut changes throughout the year.
Snow alone is the most common for 6.0 months, from October 26 to April 27. The highest chance of a day with snow alone is 13% on November 28.
Rain alone is the most common for 6.0 months, from April 27 to October 26. The highest chance of a day with rain alone is 28% on August 15.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Sisimiut experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.2 months, from April 20 to November 27, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around August 11, with an average total accumulation of 2.5 inches.
The rainless period of the year lasts for 4.8 months, from November 27 to April 20. The least rain falls around January 5, with an average total accumulation of 0.1 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Sisimiut experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 8.0 months, from September 29 to May 29, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around November 19, with an average total liquid-equivalent accumulation of 0.7 inches.
The snowless period of the year lasts for 4.0 months, from May 29 to September 29. The least snow falls around August 17, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
Due to its extreme latitude, Sisimiut experiences polar day (also known as the midnight Sun) during the summer. The precise start and end dates of polar day and night vary from year to year and depend on the precise location and elevation of the observer, and the local topography.
In the summer in Sisimiut during 2019, the Sun is continuously above the horizon for 1.3 months, rising at 1:51 AM on June 2, and not setting again until 1:22 AM on July 11.
Hours of Daylight and Twilight
Daylight saving time (DST) is observed in Sisimiut during 2019, starting in the spring on March 30, lasting 6.9 months, and ending in the fall on October 26.
Sunrise & Sunset with Twilight and Daylight Saving Time
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The perceived humidity level in Sisimiut, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Sisimiut experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 7.4 months, from September 29 to May 10, with average wind speeds of more than 9.0 miles per hour. The windiest day of the year is December 3, with an average hourly wind speed of 10.9 miles per hour.
The calmer time of year lasts for 4.6 months, from May 10 to September 29. The calmest day of the year is July 14, with an average hourly wind speed of 7.1 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Sisimiut varies throughout the year.
The wind is most often from the south for 1.4 weeks, from August 2 to August 12, with a peak percentage of 37% on August 10. The wind is most often from the north for 12 months, from August 12 to August 2, with a peak percentage of 43% on January 1.
Sisimiut is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 2.5 months, from July 9 to September 24, with an average temperature above 39°F. The day of the year with the warmest water is August 20, with an average temperature of 41°F.
The time of year with cooler water lasts for 5.5 months, from November 29 to May 12, with an average temperature below 33°F. The day of the year with the coolest water is March 2, with an average temperature of 31°F.
Average Water Temperature
Best Time of Year to Visit
To characterize how pleasant the weather is in Sisimiut throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Sisimiut for general outdoor tourist activities is from mid to late July, with a peak score in the third week of July.
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F.
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
The growing season in Sisimiut typically lasts for 3.3 months (102 days), from around June 13 to around September 23, rarely starting before May 25 or after July 5, and rarely ending before September 4 or after October 11.
Time Spent in Various Temperature Bands and the Growing Season
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
Growing Degree Days
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 2.6 months, from May 7 to July 28, with an average daily incident shortwave energy per square meter above 4.6 kWh. The brightest day of the year is June 12, with an average of 5.8 kWh.
The darker period of the year lasts for 5.0 months, from October 7 to March 6, with an average daily incident shortwave energy per square meter below 1.2 kWh. The darkest day of the year is December 22, with an average of 0.0 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Sisimiut are 66.939 deg latitude, -53.674 deg longitude, and 69 ft elevation.
The topography within 2 miles of Sisimiut contains very significant variations in elevation, with a maximum elevation change of 1,549 feet and an average elevation above sea level of 204 feet. Within 10 miles contains very significant variations in elevation (2,398 feet). Within 50 miles contains large variations in elevation (5,971 feet).
The area within 2 miles of Sisimiut is covered by sparse vegetation (36%), snow and glaciers (25%), and grassland (24%), within 10 miles by water (48%) and snow and glaciers (21%), and within 50 miles by water (52%) and sparse vegetation (14%).
This report illustrates the typical weather in Sisimiut, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Sisimiut.
For each station, the records are corrected for the elevation difference between that station and Sisimiut according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Sisimiut is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Sisimiut and a given station.
The stations contributing to this reconstruction are: Sisimiut /Holsteins (64%, 2.5 kilometers, south) and Sisimiut Airport (36%, 2.8 kilometers, northwest).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.